Electromagnetically driven liquid pump for toys



Jan. 7, 1964 H. FALLER 3,116,695

ELECTROMAGNETICALLY DRIVEN LIQUID PUMP FOR TOYS Filed Feb. 27, 1962 2. M h E L v u r. h 8 W m A 5 H w M F 1 1 -255 I u 6 7 m" 2 w 0 I 3 0 00 I ll 8 N5 SN 7 u |ll|- l u. 1 [6, m 2 n v it 1 w- U iifi States Patented Jan. 7, 1%64:

3,116,695 ELECTROMAGNETMALLY DRIVEN LIQUID PUMP FGR TOYS Hermann Falter, Gutenbaeh, Black Forest, Germany Filed Feb. 27, N62, Ser. No. 175,974 Claims priority, application Germany Mar. 1, 1961 3 Claims. (ill. 103-53) The present invention relates to an electromagnetically driven liquid pump for toys, in which a coil which is supplied with a low voltage of an alternating current surrounds a tube of a nonmagnetic material forming the pump cylinder in which a piston of a magnetic material is slidable which contains an inlet valve. In the known toy pump of this type, the magnetic impulses for producing the piston strokes are generated by interposing a one-way rectifier in the line leading to the coil so that one half of each wave of the alternating current which is supplied to the coil is cut off.

It is an object of the present invention to provide a liquid pump for toys, the piston of which is reciprocated by the alternating effect occurring between the periodically reversed magnetic field of the coil which is supplied with alternating current and the constant magnetic field of a permanent magnet. A pump of this design may be built much more easily and inexpensively than a toy pump of the type as mentioned above. Furthermore, it has the advantage that the number of impulses for reciprocating the pump piston within a certain length of time is twice that of the piston of the known pump so that, even though it is made of the same dimensions and requires approximately the same amount of current, the pump according to the invention will convey a much greater amount of liquid than the known pump.

For attaining the constant magnetic field, an axially magnetized annular magnet which surrounds the cylinder of the piston may be mounted at one end surface of the coil. It is more preferable, however, to provide such an annular magnet on each end surface of the coil, whereby the length of the piston strokes will be considerably increased. The same effect may also be attained if the pump piston is made in the form of a bar magnet.

The pump piston is preferably held in its neutral position by springs which act upon its opposite ends.

The features and advantages of the pump according to the invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which FIGURE 1 shows diagrammatically and partly in cross section an example of the manner in which the pump according to the invention may be applied;

FIGURE 2 shows an enlarged longitudinal section of the pump; while FIGURE 3 shows a longitudinal section of the pump piston on a still larger scale.

As illustrated in the drawings, the cylinder 1 of the pump according to the invention consists of a cylindrical tube with a smooth inner surface which is made, for example, of plastic. This cylinder 1 is surrounded by a coil 2 which is secured to the cylinder approximately at the center of its length, for example, by being tightly fitted thereon. Coil 2 has a length considerably less than that of cylinder 1, amounting, for example, to approximately one third of the length of the cylinder and it is designed for being energized by a harmless voltage of alternating current which is stepped down, for example, to 8 to 24 volts. The two end surfaces of coil 2 engage upon axially magnetized annular magnets 3 and 4 which also surround cylinder 1. The poles of these two magnets are arranged symmetrically insofar as both of them engage, for example, with their south poles S upon the end surfaces of the coil. Magnets 3 and 4 which are preferably made in the form of ceramic ferrite magnets are held together with coil 2 in the axial direction by a two-part housing 5. The cylinder 1 contains a tubular piston 6 of a magnetic material, for example, stainless steel, which is slidable therein in the axial direction. Piston 6 has a length slightly greater than that of coil 2. It is normally held in its neutral position by a pair of weak coil springs 7 and 8 which act upon its two end surfaces in such a manner that one end surface of the piston is substantially in alignment with the end surface of coil 2 which is located at the pressure side of the pump, that is, at the upper side of FIGURE 2, while the other end surface of piston 6 at the suction side of the pump projects beyond the other end surface of coil 2.

The two coil springs 7 and 8 supported on shoulders 9 and 10' at the inside of connecting tubes 9 and 10 which are fitted tightly over the ends of cylinder 1 and are therefore preferably made of rubber or a rubberlike plastic. One or both connecting tubes 9 and 10 are adapted to receive connecting lines which may be fitted over or into the ends of tubes 9 and 10.

For sealing the pump piston 6 relative to the wall of cylinder 1, tubular gaskets 11 and 12 of rubber or a rubberlike plastic are partly fitted into the ends of piston 6. As illustrated in FIGURES 2 and 3, these gaskets 11 and 12 are provided with enlarged collars 13 and 14 which project from the ends of piston 6, and slidably engage with the inner wall of cylinder 1. Piston 6 contains an inlet valve which, in the particular embodiment of the invention as illustrated, consists of a nozzlelike part 15 which projects into the piston chamber from the sealing gasket 11, 13 at the suction side of the piston and is provided with transverse cuts 16 forming valve flaps.

The piston stroke is attained as the result of the alternating effect between the continuously changing magnetic held of coil 1 which is supplied with alternating current and the constant magnetic fields of the two annular magnets 3 and 4. Thus, for example, if the two annular magnets 3 and 4 are arranged as illustrated in FIGURE 2, piston 6 will move downwardly toward the suction side of the pump so as to carry out a suction stroke when a north pole occurs at the end of coil ll facing in this direction, and after the change of polarity it will move in the opposite direction so as to carry out the compression stroke. In the first case, the piston will be attracted by the south pole of the annular magnet 3 at the suction side, and in the second case it will be repelled. The pump can therefore operate even though an annular magnet is provided only at one end of coil 1. If, however, as shown in the drawings, both ends of coil 1 are provided with annular magnets with a symmetrical arrangement of their poles, the propulsion of piston 6 will be considerably increased since at each change of polarity one annular magnet repels the piston While at the same time the other magnet attracts the piston.

In the particular embodiment of the invention as illustrated, the pump is provided with only one inlet valve 15 within the pump piston 6. The pump must in this case be arranged in the manner as illustrated in FIGURE 1 that the intake tube 9 is so deeply immersed into a supply of liquid F that only a very small suction head occurs. Due to the inertia of the head of liquid, an overpressure then occurs in front of the inlet valve 15 in the chamber of piston 6 while moving down rapidly, whereby the inlet valve is opened against a low discharge pressure. If the pump according to the invention is arranged as illustrated in FIGURE 1, it is therefore not necessary to provide it with a separate pressure valve at the pressure side of the stationary cylinder 1, although such an additional valve could be provided if desired. The heat which is developed in coil 2 during the operation of the pump is carried oil by the flow of liquid passing through the piston 6 and the cylinder 1.

FIGURE 1 shows an example of the manner in which the pump P according to the invention may be employed for propelling a water wheel. As already mentioned, the intake tube 9 is then immersed into a supply of liquid F in a small tank 18, while a tube 19 is connected to the outlet tube 1%} and terminate into a runoff gutter 26 which projects at a downwardly inclined angle from a wall portion 21 imitating a hillside. The free end of discharge tube 2% extends through the wall of a house 22 in which a water wheel 23 is rotatably mounted above the tank 138. The liquid which is conveyed by the pump therefore flows upwardly in the pressure line '19 and then downwardly along the runoff gutter 2t} and upon the blades of the water wheel 23, from which it runs back into the tank 18.

It is also within the concept of the invention to design the pump piston in the form of a bar magnet, in which case the annular magnets 3 and 4 will be omitted.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what 1 claim is:

1. A liquid pump for toys comprising a tubular cylinder of a nonmagnetic material, a coil surrounding said cylinder, a tubular piston of a magnetic material slidable within said cylinder, an inlet valve connected to one end of said piston, and a pair of annular axially magnetized permanent magnets surrounding said cylinder adjacent to the opposite end surfaces of said coil and polarized symmetrically relative to said coil, said piston being adapted to be reciprocated in its axial direction by the alternating effect occurring between the magnetic fields of said permanent magnets and the periodically reversed magnetic field of said coil when said coil is energized by an alternating current.

2. A liquid pump for toys comprising a tubular cylin- 4 der of a nonmagnetic material, a coil surrounding said cylinder, a tubular piston of a magnetic material slidable within said cylinder, an inlet valve connected to one end of said piston, 21 pair of annular axially magnetized permanent magnets surrounding said cylinder adjacent to the opposite end surfaces of said coil and polarized symmetrically relative to said coil, said piston being adapted to be reciprocated in its axial direction by the alternating effect occurring between the magnetic fields of said permanent magnets and the periodically reversed magnetic field of said coil when said coil is energized by an alternating current, and spring means acting upon both ends of said piston for normally maintaining said piston in its neutral position.

3. A liquid pump for toys comprising a tubular cylinder of a nonmagnetic material, a coil surrounding said cylinder, a tubular piston of a magnetic material slidable within said cylinder, at least one permanent magnet acting upon at least one end of said piston, said piston being adapted to be moved in its axial direction by the altermating effect occurring between the constant magnetic field of said permanent magnet and the periodically reversed magnetic field of said coil when said coil is energized by an alternating current, spring means acting upon at least one end of said piston for normally maintaining said piston in its neutral position, tubular gaskets of a resilient material inserted into the ends of said piston and having enlarged collar portions projecting from said ends and slidabtly engaging with the inner wall of said cylinder for sealing said piston relative to the wall of said cylinder, and an inlet valve of a resilient material integral with one of said gaskets and inserted into the lower end of said piston and having transverse cuts in its inner end forming valve flaps.

References Cited in the file of this patent UNITED STATES PATENTS 2,177,795 Von Delden Oct. 31, 1939 2,474,349 Dickey et a1. June 28, 1949 2,768,580 Parker Oct. 30, 1956 FOREIGN PATENTS 207,692 Austria Feb. 25, 1960 719,022 Germany Mar. 27, 1942 28,872 Great Britain of 

1. A LIQUID PUMP FOR TOYS COMPRISING A TUBULAR CYLINDER OF A NONMAGNETIC MATERIAL, A COIL SURROUNDING SAID CYLINDER, A TUBULAR PISTON OF A MAGNETIC MATERIAL SLIDABLE WITHIN SAID CYLINDER, AN INLET VALVE CONNECTED TO ONE END OF SAID PISTON, AND A PAIR OF ANNULAR AXIALLY MAGNETIZED PERMANENT MAGNETS SURROUNDING SAID CYLINDER ADJACENT TO THE OPPOSITE END SURFACES OF SAID COIL AND POLARIZED SYMMETRICALLY RELATIVE TO SAID COIL, SAID PISTON BEING ADAPTED TO BE RECIPROCATED IN ITS AXIAL DIRECTION BY THE ALTERNATING EFFECT OCCURRING BETWEEN THE MAGNETIC FIELDS OF SAID PER- 